Between January 1970 and December 1991, 201 patients < or = 40 years of age underwent coronary artery bypass graft surgery (CABG). Group 1 (1970 to 1980, n = 119) and group 2 (1981 to 1991, n = 82) corresponded to the eras before and after the onset of percutaneous transluminal coronary angioplasty (PTCA), respectively, and were analyzed for trends in patient profile, treatment, and risk factors for coronary artery disease (CAD): smoking, hypertension, hypercholesterolemia, diabetes, and family history. Mean age at operation was similar in the groups (1, 37 +/- 3.4 years; 2, 36 +/- 3.1 years). Women made up 18% of group 1 and 27% of group 2 (P = .048). Risk factor profile differed in the two groups: group 1 had more smokers (80%) than group 2 (68%) (P = .085), fewer patients with hypercholesterolemia (1, 37%; 2, 52%; P = .065), and significantly fewer diabetics (1, 10%; 2, 25%; P < .043). Mean preoperative New York Heart Association (NYHA) class was 3.2 in group 1 and 3.0 in group 2. The distributions of single-, double-, and triple-vessel CAD were similar in the groups. Preoperative myocardial infarction occurred in 55% of group 1 versus 61% in group 2 (P = NS). No group 1 patient received PTCA before CABG, but PTCA was performed in 15 group 2 patients. Left internal mammary artery grafts were used in 4% of group 1 and 57% of group 2 patients. CABG operative mortality was 7.0% in group 1 and 1.2% in group 2.(ABSTRACT TRUNCATED AT 250 WORDS)